In the prior art there are a number of inventions directed to stabilising ships and other water borne vessels and/or equipment used on water.
Such inventions may be directed to hydrodynamic or hydrostatic features of hulls or hydrofoils, and may include equipment to decrease pitch or roll or unwanted vessel movement. The inventions may be directed to self-righting, collapsible and unsinkable systems. They may be directed to the particular design and construction of a floating hull. They may include such equipment as hydroplane blades or outriggers designed to improve both the stability of the vessel or object on the water or improve the flotation of the vessel or object.
Such equipment may be designed specifically to improve the stability and flotation of a vessel or object in motion, whilst others may be particularly designed to improve the stability and flotation of vessels or objects at rest on a body of water.
For example, a boat hull may be specifically designed to provide a space under the deck between the bow stern and bottom of the boat to provide buoyancy for the hull as disclosed in New Zealand Patent No. 302612. Yet other systems may employ the use of floats connected to a central hull in a typical trimaran design as in New Zealand Patent Specification No. 237938 and 241329. In these examples the system in effect becomes multi-hulled, with two side floats positioned on either side of the central float (hull).
The position and operation of such floats may be adjustable as in the above mentioned patent specifications, or may be fixed as a side extending rigid float as described in relation to sail boards in Patent Specification 206254.
In the systems described, the floats are attached above the waterline relative to the main vessel, with the side floats themselves being partially submerged (particularly when the vessel is stationary).
Retractable floats or outrigger stabilisers for aquatic vehicles are described in a number of prior art documents including New Zealand Patent No. 175973 and 149659. In such situations the outrigger stabilisers extend on each side of a vessel from points of attachment adjacent the top of each side of the vessel.
However, there are problems associated with all of the above systems. In the scenario where a space is provided under the deck of the boat between the bow and stern and bottom to provide buoyancy for the hull, the buoyancy does not necessarily improve the stability of the vessel.
Typically a at rest on a body of water will rock due to the impact of wind, waves and currents. When the vessels are small (such as in the case of small aluminum dinghies or sailboats), the relative buoyancy of the vessel tends to make it more unstable than is the case for larger, heavier vessels. Accordingly, small vessels or other objects tend to rock more vigorously when at rest in most bodies of water.
In systems relying on laterally disposed floats connected to a central hull in a typical trimaran arrangement, the floats are designed to minimise the rolling and rocking motion of the boat and provide additional flotation for the boat. The point of attachment of most of the floats is typically at deck level or attached toward the upper part of the main hull. Where such systems rely on retractable floats, they typically involve complex pivoting assemblies to allow the float to be folded against the hull or raised out of the water (when the float is not required). The overall design of the floats is typically bulky and they are somewhat cumbersome when retracted. Further, the retractable systems typically operate on hydraulic/pneumatic systems requiring suitable pressure to operate them.
Systems that include rigid floats permanently attached to the sides of a vessel (whilst providing some stability to the vessel), can become cumbersome and undesirable when the vessel is being stored, or where the stabilising/flotation apparatus is not required.
Accordingly, it would be advantageous to have a flotation and stabilising system for water borne objects that:    a) assists in decreasing the pitch, rocking, roll, or similar unwanted vessel movement particularly when the vessel or object is at rest on the body of water;    b) is a system where the flotation/stabilising apparatus is available when required and is easily positioned in to its operating position, without the need for hydraulic or powered systems, or can be raised or lowered without the need for hydraulic or powered systems; and    c) is simple to manufacture and cost effective to produce; and    d) can be used with a range of water borne vessels, sporting equipment and objects, particularly smaller vessels and the like, as and when required; and    e) is easy to attach to a vessel, sporting equipment or object by any home handy person, or can be an optional extra for a range of vessels sold with or as an attachment to said vessels; and    f) is a compact system which in its non-operating position is not bulky, nor gets in the way.
It is an object of the present invention to at least address the foregoing problems and/or provide the public with a useful choice.
Further aspects and advantages of the present invention will become apparent from the ensuing description that is given by way of example only.